''Shamatha meditation is a method for achieving previously inconceivable levels of concentration. Author B. Alan Wallace, an active participant in the much-publicized dialogues between Buddhists and scholars, has more than 20 yearsΓÇÖ practice in the discipline, some of it under the guidance of the Dalai Lama. This book is a definitive presentation of his knowledge of shamatha. It is aimed at the contemporary seeker who is distracted and defocused by the dizzying pace of modern life, as well as those suffering from depression and other mental maladies. Beginning by addressing the inherent problems that follow from an inability to focus, Wallace moves on to explore varying levels of meditation. The result is an interior travelogue that recounts an exciting, rewarding "expedition of the mind," tracing everything from the confusions at the bottom of the trail to the extraordinary clarity and power that come with making it to the top.''

It should be noted that:

This book has steps for beginners, intermediary and advanced mediators. 
This book does NOT focus too much on conceptual or historical aspect of Shamatha/Samatha meditation- for this, search for the Suttas/Sutras. It should be noted, too, that every school(Theravada, Mahayana, Vajrayana/Tantrayana) gives a different flavor and place for Shamatha/Samatha according to each Tradition.